Question

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

#include "structs.h"
#include "server.h"
#include "client.h"


int main(void)
{

  pid_t pid;
  int mypipe[2];
  int otherPipe[2];

  if(pipe(mypipe))
    {
      printf("Error in making a pipe");
    }
  if(pipe(otherPipe))
    {
      printf("Error creating another pipe");
    }
  if((pid=fork()) == -1)
    {
      perror("fork");
      exit(1);
    }
  printf("Child ID: %d" , pid);
  if(pid == 0)
    {
      close(mypipe[1]);
      close(otherPipe[0]);
      client *c = new client(mypipe[0], otherPipe[1]);
      wait(NULL);
      //c->startProgram();
      //return EXIT_SUCCESS;
    }
  else
    {
      printf("Yo");
    close(mypipe[0]);
    close(otherPipe[1]);
    server s;
    s.fdIn = otherPipe[0];
    s.fdOut = mypipe[1];
    s.startServer();
    //wait(NULL);
    //return EXIT_SUCCESS;
    }
}

Above is my code. The child process runs fine (If I remove that comment obviously), however the else never gets executed (Or am I missing something in the terminal?).

Here’s a screen shot of the output: https://i.stack.imgur.com/MawUJ.png

Any ideas on why it’s not going to the else/parent spot?

Thanks!

Answer 1

Could it be because stdio is buffered? Try flushing output after printfing the child id. Or adding a \n. Or fprintfing it to stderr.

EDIT: Just to clarify. My guess is not that it’s the reason it’s not getting to parent, for it is, it is why you do not see the output you expect.